What are the solutions to the equation 2x^2-x=21 ?

The solutions to the equation 2x^2-x=21 are x= 7/2 ,x=-3

Find the zeros of 2x^2-x=21

The zeros of 2x^2-x=21 are x= 7/2 ,x=-3

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2 x^{2} - x = 21

x = \frac{7}{2}, x = - 3

Decimal Notation

x = 3.5, x = - 3

Solution steps

2 x^{2} - x = 21

Move

21

to the left side

2 x^{2} - x - 21 = 0

Solve with the quadratic formula

x_{1, 2} = \frac{- ( - 1 ) \pm ( - 1 ) ^{2} - 4 \cdot 2 ( - 21 )}{2 \cdot 2}

(- 1)^{2} - 4 \cdot 2 (- 21) = 13

x_{1, 2} = \frac{- ( - 1 ) \pm 13}{2 \cdot 2}

Separate the solutions

x_{1} = \frac{- ( - 1 ) + 13}{2 \cdot 2}, x_{2} = \frac{- ( - 1 ) - 13}{2 \cdot 2}

x = \frac{- ( - 1 ) + 13}{2 \cdot 2} : \frac{7}{2}

x = \frac{- ( - 1 ) - 13}{2 \cdot 2} : - 3

The solutions to the quadratic equation are:

x = \frac{7}{2}, x = - 3

(7 x + 2)^{2} = 27

\frac{z}{1 - i} + \frac{2}{i} = 3

3 x^{- 2} y^{- 5}

1050

\frac{- 8 \cdot 1 0 ^{7}}{- 4 \cdot 1 0 ^{6}}

What are the solutions to the equation 2x^2-x=21 ?
The solutions to the equation 2x^2-x=21 are x= 7/2 ,x=-3
Find the zeros of 2x^2-x=21
The zeros of 2x^2-x=21 are x= 7/2 ,x=-3